نتایج جستجو برای: equivalent hydraulic conductivity
تعداد نتایج: 212988 فیلتر نتایج به سال:
The generalized conceptual model for a fractured bedrock aquifer consists of low-permeability matrix blocks separated by highly permeable fractures that act as preferential pathways for ground water flow. The National Research Council (NRC 1996) summarizes three approaches for simulating ground water flow in fractured aquifers. The most common approach is to represent the system with an equival...
We present a methodology to account for the stochastic nature of hydraulic conductivity during the design of pump-and-treat systems for aquifer cleanup. The methodology (I) uses a genetic algorithm to find the global optimal solution and (2) incorporates a neural network to model the response surface within the genetic algorithm. We apply the methodology for a real example and different optimiz...
IInfiltration rate and hydraulic conductivity are immensely important parameters for evaluating the hydrology of subsurface environments. Specifically, in disposal wells schemes and in artificial recharge plans both properties must be correctly assessed to better analyze the performance of these installations. In a new research, tanker water and rainfall runoff were injected into a 22.5 m deep ...
Contaminant transport in a strongly heterogeneous stratified formation whose log hydraulic conductivity distribution has a variance greater than unity is investigated. Four kinds of waste leakage scenario are studied. They are: (1) continuous waste leakage from landfills; (2) temporal waste leakage from landfills; (3) continuous deepwell injection wastes; and (4) temporal deep-well injection wa...
soil hydraulic properties are key soil physical characteristics that are required to conduct soil and water related studies such as irrigation and drainage. in this study, three indirect methods: inverse modeling, pedo-transfer function, and the semi-physical method of arya et al., were compared in a sandy loam soil to estimate soil moisture retention and unsaturated hydraulic conductivity curv...
Estimation of soil hydraulic and solute transport parameters is important to provide input parameters for numerical models simulating transient water ̄ow and solute transport in the vadose zone. The Levenberg±Marquardt optimization algorithm in combination with the HYDRUS-1D numerical code was used to inversely estimate unsaturated soil-hydraulic and solute transport parameters from transient m...
Rose plants (Rosa x hybrida L. CV. Kardinal, grafted on Natal Brier) were grown in UC mix and in coconut coir. Water release curves and hydraulic conductivity of the media were measured. Water tensions in the media were maintained within a predetermined narrow range by tension-actuated irrigation, using high-flow electronic tensiometers. Transpiration rate of plants sitting on load cells was me...
It is widely recognized that groundwater flow and solute transport in natural media are largely controlled by heterogeneities. In the last three decades, many studies have examined the effects of heterogeneous hydraulic conductivity fields on flow and transport processes, but there has been much less attention to the influence of heterogeneous porosity fields. In this study, we use porosity and...
In order to better manage and monitor fluid flow and migration of chemicals in gas and liquid phases, a fundamental understanding and knowledge of the saturation dependency of permeability, diffusion and electrical conductivity in a porous medium is required. The initial fundamental formulations and recent research for characterization of transport properties in porous media are discussed. To i...
Comparison of the root system growth and water transport of southern pine species after planting in different root-zone environments is needed to guide decisions regarding when, and what species to plant. Evaluation of how seed source affects root system responses to soil conditions will allow seed sources to be matched to planting conditions. The root growth and hydraulic conductivity of three...
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